Arterial embolism, leading to embolic ischemia or stroke, is one of the most dreadful complications of cardiac, aortic and vascular procedures, diagnosed in 1-22% of patients undergoing cardiovascular surgery. Even more frequently, in up to 86% of cases, patients undergoing heart, valve, coronary artery bypass, aortic surgery, cardiac catheterization, or even simple endovascular interventions experience subclinical embolic events as recorded by transcranial Doppler or magnetic resonance imaging (MRI). These embolic events can lead to cognitive impairment, disability, extremity ischemia, multiple organ failure, dementia, and death having a significant impact on patients' recovery. With more than 1.2 million cardiovascular procedures performed in the United States alone, this issue has a significant socio-economic impact.
The main sources of emboli in this setting reside in the heart, heart valves, thoracic aorta, and great vessels when these structures are intervened thereon (i.e. when an emboligenic procedure is performed). Even simple cardiac catheterization with an endovascular catheter can induce microtrauma of the atherosclerotic thoracic aorta leading to formation of embolic particles with subsequent embolic brain, liver, kidney and extremity injury ranging from latent ischemic foci to a massive or even fatal event. Multiple devices are known that attempt to prevent embolization of the carotid arteries during endovascular and cardiac interventions by using different types of filters, deflection devices, endoluminal balloons, shields, or other embolic traps or deflectors. These anti-embolic devices, however, have not received wide acceptance in surgery of the heart, heart valves and thoracic aorta due to their complexity and invasive character with the risk of additional trauma to the inner vessel wall resulting in a high risk to benefit ratio. Known devices require insertion of additional hardware into the arterial system or aorta, a procedure that is known by itself to be associated with all classical risks of endovascular intervention, including aortic dissection, bleeding, thrombosis, and arterial embolization. One known intra-aortic filter device that is inserted into the ascending portion of the thoracic aorta via an aortic cannula to capture potential embolic material released from the heart and aortic wall during heart surgery was found to be quite difficult to implement and was reported to be associated with major trauma to aortic wall and acute aortic dissection.
Aside from introducing hardware into the patient and causing the aforementioned problems, intravascular filters are not able to capture embolus smaller than the pore size of the available devices (currently 60-140 μm) resulting in cerebral microembolization. Furthermore, the placement of the filter by itself may produce cerebral emboli. For example, the mere passing of a guide wire into a carotid artery generates approximately 40,000 microemboli, with a significant percentage of small, less than 60 μm, particles that are not retained by standard filters. Therefore, in spite of multiple innovations in the field of anti-embolic devices, the problem of arterial emboli and stroke during cardiovascular surgery is far from being resolved. As such, there remains room for variation and improvement within the art.